Sunset yellow FCF and oestrogen receptor activity in lab cells
What it found
In lab tests on human breast cancer cells, sunset yellow FCF activated the human oestrogen receptor.
It reached half its maximum effect at a concentration of 220 nM.
What they found
Animal and lab studies
Oestrogen receptor activation
In human breast cancer cells, sunset yellow FCF turned on the oestrogen receptor. It reached half its maximum effect at a concentration of 220 nM. Tartrazine did the same at 160 nM.
Potency compared to oestrogen
Both food colourings were about 50 times less effective than natural oestrogen at activating the receptor in these cells. However, they were stronger activators than some preservatives called parabens.
Blocking the effect
A drug that blocks the oestrogen receptor stopped sunset yellow FCF from activating it. This confirmed the colouring was working through the oestrogen receptor in the lab cells.
Other findings
Possible levels in people
The authors calculated that heavily exposed people might reach blood levels of 640 nM for sunset yellow FCF. This estimate assumed only 10% is taken in and that the body clears half of it. That level is higher than what activated the receptor in their cell tests.
What the authors conclude
- They suggest that sunset yellow FCF and tartrazine can act like oestrogen in lab tests by turning on the human oestrogen receptor.
- They say these colourings are not the sole cause of the liver disease but might be one contributing factor alongside other things.
- They note that high dietary intake could potentially lead to blood levels capable of having an oestrogen-like effect in people.
How it was done
The authors wanted to find out if chemicals linked to a liver disease called primary biliary cirrhosis might act like the female hormone oestrogen. They suspected that long-term exposure to such chemicals could play a part in this disease, which mostly affects women after menopause.
They built a screening test using human breast cancer cells grown in the lab. They exposed these cells to various chemicals, including food colourings, to see which ones turned on the human oestrogen receptor. They measured how much of each chemical was needed to activate the receptor.
What it can’t tell you
- These results come from breast cancer cells in a dish, so they cannot show what happens in a living human body.
- The calculations about blood levels are estimates based on assumptions, not measurements taken from real people eating the colouring.
- Cell tests cannot prove that eating sunset yellow FCF causes liver disease or changes hormone balance in shoppers.
Who paid
- Authors work at
- Newcastle University, United Kingdom
The paper
- Title
- Tartrazine and sunset yellow are xenoestrogens in a new screening assay to identify modulators of human oestrogen receptor transcriptional activity
- Type
- Study
- Evidence
- Animals and lab studies
- Summarised from
- Full text
- Cite
- Axon A, May FE, Gaughan LE, Williams FM, Blain PG, Wright MC (2012). Tartrazine and sunset yellow are xenoestrogens in a new screening assay to identify modulators of human oestrogen receptor transcriptional activity. Toxicology. doi:10.1016/j.tox.2012.04.014Free full textPubMed 22562034DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error